Tag trailer files with the tractor they belong to, by UUID

Problem

Nothing in a unit file says which tractor a trailer belongs to. Anything pairing them automatically has to guess from the name, and for most trailers the name gives nothing away: a Ballista Artillery Trailer does not read as belonging to a Destrier Siege Vehicle.

There are 45 trailers in the data, split across two mechanisms that do not overlap:

• 22 combat vehicles carrying a <trailer> block
• 23 support vehicles carrying SV Chassis Mod [Trailer]

What to add

An optional towedBy block on each trailer file, one line per tractor, giving the tractor's UUID then a pipe then its chassis and model:

<towedBy>
019f583e-e7a9-7a3a-bc7b-1d5353eb104a|Destrier Siege Vehicle
</towedBy>

The UUID is the link and the name is for people. Anything reading the file splits on the first pipe and ignores the rest, so a unit can be renamed without breaking a tag, but a diff still shows what it points at.

Pipe is the separator because a UUID cannot contain one, and mm-data already uses it that way in name_changes.txt.

Several trailers take more than one tractor: GESV trailers fit any of three GESV variants, HMRV trailers either Oppie, and the J-27 trailer any of three J-27 variants. One line each.

Ten Gun Trailer variants are deliberately left untagged. They are designed to be hauled by any vehicle with a hitch, and their own fluff says so.

Every trailer and its tractor

Tagged: one tractor

Trailer	Trailer UUID	Tractor	Tractor UUID
Ballista Artillery Trailer	019f583e-e7a8-7143-8855-aa89c2439f30	Destrier Siege Vehicle	019f583e-e7a9-7a3a-bc7b-1d5353eb104a
Bokkusu Support Trailer	019f583e-e78e-73e7-a4cf-c9fac8b7e5cd	Teppō Artillery Vehicle	019f583e-e798-785b-ad84-ef985b4ec148
Tenmaku Command Trailer	019f583e-e797-7d1c-af4d-f859f223fc85	Teppō Artillery Vehicle	019f583e-e798-785b-ad84-ef985b4ec148
Galaport Ground Trailer	019f583e-eaec-7b17-9b33-5c0e62d441c3	Galaport Ground Tug	019f583e-eaee-7a62-b46b-a0cfb832b36d
Mobile Long Tom LT-MOB-25 (Ammunition Carriage)	019f583e-e2d0-7d13-aa5e-eac6343119aa	Mobile Long Tom LT-MOB-25	019f583e-e2d3-70be-af0d-5de4c64bcc99
Mobile Long Tom LT-MOB-25 (Support Carriage)	019f583e-e2d1-74df-a490-5f659ca66f91	Mobile Long Tom LT-MOB-25	019f583e-e2d3-70be-af0d-5de4c64bcc99
Mobile Long Tom LT-MOB-25F (Ammunition Carriage)	019f583e-e9b8-792d-9453-e1ecdbb52537	Mobile Long Tom LT-MOB-25F	019f583e-e9c0-790e-9de6-27b28b60cab2
Mobile Long Tom LT-MOB-25F (Ammunition Loader Carriage)	019f583e-e9ba-7d70-9dfb-e3ae92a6bc1b	Mobile Long Tom LT-MOB-25F	019f583e-e9c0-790e-9de6-27b28b60cab2
Mobile Long Tom LT-MOB-25F (Drone Command Carriage)	019f583e-e9bc-7604-8b01-53383093b165	Mobile Long Tom LT-MOB-25F	019f583e-e9c0-790e-9de6-27b28b60cab2
Mobile Long Tom LT-MOB-25F (Support Carriage)	019f583e-e9bd-7e50-85a5-99fb0c456d79	Mobile Long Tom LT-MOB-25F	019f583e-e9c0-790e-9de6-27b28b60cab2
Hector Road Train Trailer Module	019f583e-e910-7643-8852-814c6e90b4f0	Hector Road Train Tractor	019f583e-e906-700d-b94b-51df5ac8b568
Hector Road Train Trailer Module (Liquid)	019f583e-e907-7d40-b85a-70a5c8b4fc5f	Hector Road Train Tractor	019f583e-e906-700d-b94b-51df5ac8b568
Hector Road Train Trailer Module (Livestock)	019f583e-e90a-7725-ae3b-6fd6beb2e32d	Hector Road Train Tractor	019f583e-e906-700d-b94b-51df5ac8b568
Hector Road Train Trailer Module (Passenger)	019f583e-e90d-750f-82f4-4ae3cd916c2a	Hector Road Train Tractor	019f583e-e906-700d-b94b-51df5ac8b568
Hector Road Train Trailer Module (Refrigerated)	019f583e-e90f-72ae-873e-3d4014ac2ff3	Hector Road Train Tractor	019f583e-e906-700d-b94b-51df5ac8b568
Dreadnought Mk II Land Trailer Configuration #1	019f583e-ec04-78a7-99c8-2e2cd5ab7b15	Dreadnought Mk II Land Train	019f583e-ec0a-7340-a6c3-f2700c3efca1
Dreadnought Mk II Land Trailer Configuration #2	019f583e-ec05-7443-ad84-66d9c73936fa	Dreadnought Mk II Land Train	019f583e-ec0a-7340-a6c3-f2700c3efca1
Dreadnought Mk II Land Trailer Configuration #3	019f583e-ec07-7895-a9cc-fee8727e7a9a	Dreadnought Mk II Land Train	019f583e-ec0a-7340-a6c3-f2700c3efca1
Dreadnought Mk II Land Trailer Configuration #4	019f583e-ec09-7466-9949-cf9e91650d70	Dreadnought Mk II Land Train	019f583e-ec0a-7340-a6c3-f2700c3efca1
Gienah-Durapaq Elite Land Train (Trailer) Series 3T	019f583e-eaf4-7edb-81b9-282313c635d6	Gienah-Durapaq Elite Land Train (Tractor) Series 3	019f583e-eaf1-7d35-86c5-5791aa3d7f1b
Prairie Schooner Module	019f583e-eb84-7391-9229-28fc3cc437ef	Prairie Schooner Land Train	019f583e-eb81-779a-91c5-b60821553625
TGV Omni Railcar Primary Configuration	019f583e-eadc-75eb-992c-2dc58ce46ff1	Adelante Passenger/Cargo Train	019f583e-eaba-77cc-bbc6-e0ce02cb8ced
TGV Omni Railcar Primary (Luxury)	019f583e-ead9-788f-9051-cd4db6b63371	Adelante Passenger/Cargo Train	019f583e-eaba-77cc-bbc6-e0ce02cb8ced
TGV Omni Railcar A (Passengers)	019f583e-eabe-7fb3-a5fd-7786e7c0c045	Adelante Passenger/Cargo Train	019f583e-eaba-77cc-bbc6-e0ce02cb8ced
TGV Omni Railcar B (Military Support)	019f583e-eac1-7290-a30c-99fa10f3558c	Adelante Passenger/Cargo Train	019f583e-eaba-77cc-bbc6-e0ce02cb8ced
TGV Omni Railcar C (Cargo)	019f583e-eac4-72c9-be12-f0862f962a4e	Adelante Passenger/Cargo Train	019f583e-eaba-77cc-bbc6-e0ce02cb8ced
TGV Omni Railcar D (MASH)	019f583e-eac8-7be2-a548-c275acaa1e23	Adelante Passenger/Cargo Train	019f583e-eaba-77cc-bbc6-e0ce02cb8ced
Flatbed Railcar	019f583e-ebb6-7835-9731-d012361147b1	Adelante Passenger/Cargo Train	019f583e-eaba-77cc-bbc6-e0ce02cb8ced

Tagged: several tractors

Trailer	Trailer UUID	Tractors	Tractor UUIDs
HMRV DeConAid Trailer	019f583e-e654-7265-b77a-515a1e7450b2	Oppie O-65, Oppie O-66	019f583e-e656-7f3e-8c83-5133b1d91814, 019f583e-e659-75cf-af7e-617b624a12ff
HMRV Salvage Bed	019f583e-e65c-7589-805d-1f76e53fc17c	Oppie O-65, Oppie O-66	019f583e-e656-7f3e-8c83-5133b1d91814, 019f583e-e659-75cf-af7e-617b624a12ff
GESV Trailer (Bunk)	019f583e-e8fa-705c-a86e-641d91a256aa	GESV Command Post, Field Kitchen, MASH	019f583e-e8f6-7734-b7fd-8bec3772bda2, 019f583e-e8f7-7f4d-b7a0-d300976b8c70, 019f583e-e8f9-7e9f-8ef5-1ba56493b1fe
GESV Trailer (Cargo)	019f583e-e8fc-7622-afeb-8df8291b40c6	GESV Command Post, Field Kitchen, MASH	as above
J-27 Ordnance Transport (Trailer)	019f583e-e2aa-7bd7-8fd2-8438c1749840	J-27 Ordnance Transport, (Armor), (Fusion)	019f583e-e2ac-7c60-b90c-c2d02d14e88b, 019f583e-e2a8-751c-80a0-fddf718c8945, 019f583e-e2a9-7c03-b86f-77b9fde5ffc6
J-27 Trailer (RISC) (Decoy)	019f583e-ec59-7bc8-bc9d-3f569a5e87e2	J-27 Ordnance Transport (RISC)	019f583e-ec57-7499-ae02-8726ed7a520e
J-27 Trailer (RISC) (Homing)	019f583e-ec5b-786d-a441-c1fd46bfc438	J-27 Ordnance Transport (RISC)	019f583e-ec57-7499-ae02-8726ed7a520e

Left untagged on purpose: any hitch can pull these

Trailer	Trailer UUID
Gun Trailer (Ambush)	019f583e-e815-7f18-86bf-f55a381ff1f5
Gun Trailer (Artillery/AA)	019f583e-e816-75ae-9cb5-6727cc9c9648
Gun Trailer (LRM)	019f583e-e819-76be-ad88-3c4585c7e286
Gun Trailer (Mjolnir)	019f583e-e81a-79fe-bde3-2aabb967d73a
Gun Trailer (Siege)	019f583e-e81c-7588-a08e-72392e93f659
Gun Trailer (Sniper Cannon)	019f583e-e81d-7509-94e7-9e1fc66ccb95
Gun Trailer (Stronghold)	019f583e-e81f-7bde-b967-fce369578570
Gun Trailer (Thumper)	019f583e-e820-7830-823d-89d7f62dd065
Gun Trailer (Thunderbolt)	019f583e-e822-7483-a41b-7bc86554d578
Gun Trailer (Ultra)	019f583e-e823-7606-a9e4-996ec1587602

Every other trailer in the game has a tractor. The ten Gun Trailer variants are the only ones that do not.

Notes

• Mobile Long Tom LT-MOB-95 (019f583e-e846-7a21-a33b-bfdea3a4656a) has no carriages. It rationalised the whole battery into one chassis, so it should not be tagged against any trailer.
• The pairings for Ballista, Bokkusu, Tenmaku, Galaport, HMRV and GESV came from Hammer. The rest were worked out from matching chassis and model families and are worth a check before the files are edited: Hector Road Train, Dreadnought Mk II, Gienah-Durapaq, Prairie Schooner, the Long Tom carriages, and the TGV railcars against the Adelante.

Depends on

MegaMek/megamek#8607 adds the loader support to read the tag. The files can be tagged before that lands, since an unrecognised block is ignored, but the tag does nothing until it does.